The average of marks obtained by Aakash in seven subjects is 68. His average in six subjects excluding Mathematics is 70. How many marks did he get in Mathematics ?

Options

A. 56
B. 60
C. 68
D. 82

Answer

To find out how many marks Aakash obtained in Mathematics, we can follow these steps:

1. **Calculate the total marks obtained in 7 subjects**:
- The average marks in 7 subjects = 68
- Number of subjects = 7
- Total marks in 7 subjects = Average × Number of subjects = 68 × 7

\[ \text{Total marks in 7 subjects} = 68 \times 7 = 476 \]

2. **Calculate the total marks obtained in the 6 subjects excluding Mathematics**:
- The average marks in 6 subjects = 70
- Number of subjects = 6
- Total marks in 6 subjects = Average × Number of subjects = 70 × 6

\[ \text{Total marks in 6 subjects} = 70 \times 6 = 420 \]

3. **Calculate the marks obtained in Mathematics**:
- Let the marks obtained in Mathematics be \( M \).
- We know that the total marks in 7 subjects is the sum of the marks in the 6 subjects and the marks in Mathematics.

\[ \text{Total marks in 7 subjects} = \text{Total marks in 6 subjects} + M \]
\[ 476 = 420 + M \]

4. **Solve for \( M \)**:
\[ M = 476 - 420 = 56 \]

Thus, Aakash obtained **56 marks in Mathematics**.